Jens peter hansen



J. P. HANSENA SHUTTER FOR PHOTOGRAPHIC CAMERAS. APPLICATION FILED DEC-10. 1918.

1,317,575. Patented Sept. 30, 1919.

J ENS PETER HANSEN, OF COPENHAGEN, DENMARK.

SHUTTER r03 PHOTOGRAPHIC CAMERAS.

Specification of Letters Patent.

Patented Sept. 30, 1919.

Application filed December 10, 1918. Serial No. 266,171.

To all whom it may concern:

Be itknown that I, JENs PETER HANsnn, a subject of the King of Denmark,and mmdent of Copenhagen, 10 Jacobys Alle, Denmark, have inventedcertain new and useful Improvements in Shutters for PhotographlcCameras, of which the following is a Specification.

The present invention concerns an improvement in shutters forphotographic cameras. The novel feature of the invention is the use ofbent edges on the shutter door or doors, which edges cooperate withcorresponding notches in the shutter board so that by the closing of thedoors an a1r cushion is formed (as it is very difficult for the air toescape through the narrow space between the edges of the doors and theaforesaid notches) which air cushion highly contributes to render theclosing quite noiseless, lighttightness being besides obtained in. aspecially easy and safe way, which will be 7 described later.

The invention is shown on the drawing, where:

Figure 1 shows a double door-shutter, seen from the rear-part of thecamera, the doors being open.

Fig. 2 is a section on the line IIII, Fig. 1.

On the drawing 1 is the shutter-board the back of which has a projectingpart 2,which cooperates with the doors. These consist of a door-plate 3with bent edges or flanges 4: and 5, which exactly inclose theprojecting part 2. One of the joining edges of the doors may have aprojecting felt strip 6 and the other a corresponding strip 7 in orderto attain light-tightness where the doors meet. The doors are fitted onturning rollers 8 and 9, which, in proper way are mounted in strips 23and 24 on the shutter board. In order to secure synchronicalcooperation, the

two rollers are in known manner provided with a crossed cord 10 and inorder to secure the closing of the doors, a coil spring 11 is secured toone of the rollers the other end of the coil spring being fastened tothe shutter board.

By shutters with bent edges (especially if the edges as those on thedrawings 12, are bent in the direction of the lens) absolutelight-tightness around the pro ecting part 2 can be obtained, if theedges are given a certain height even if the doors are adjusted in suchway, that they stop at a distance of 3-3 m. m. from the projecting part2, the light being unable to escape in the direction of the plate or thefilm, as is the case, when the doors have no bent edges, but beingforced in regressive direction against the shutter-board. (It issupposed, that the shutter is mounted behind the lens). And thepossibility of stopping the doors by their closing some distance fromthe shutter board, (which can be done by suitable means), without thedoor striking the shutter board, and yet without endangering thelight-tightness. is of the greatest importance for the attaining of aquite noiseless closingand without such no really good studio-shuttercan be obtained.

It should further be mentioned, that the felt strips 6 and 7 may beapplied in such way, that they are pressed against each other by theclosing of the doors, which contributes to an even stopping The bentedges of the doors must besides fit tightly to the projecting part ofthe shutter frame and the bent edges of the one door must be over theedges of the other door, so that by the closing an air cushion is formedwhich excludes any shaking and sound. In

like manner, the edges of the device described will secure absolutelight-tightness. Having now described my invention what I claim as newand desire to secure by Letters Patent, is

1. In a photographic camera, a shutter frame having a projectingportion, and a shutter formed of two plates hinged to the frame andprovided with inwardly extending flanges engaging the edges of theprojecting portion of the frame,'the edges of the said plates overlyingone another when closed.

2. In a photographic camera, a shutter frame having a projecting portionand a shuttei' formed of two plates hinged to the In testimony whereof Iaffix my signature shuttef fragjne and provided with1 inwafrdlly inpresence of two witnesses.

extenc ing .a nges en zwing the e ges 0 tie 1 T said projecting portionof the frame, the JENS PETER IIANSILL' edges of the plates overlying oneanother Witnesses:

when closed and provided With packing E. SLECKHAHN,

strips. CHAS. UNDER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

